While that's in testing, we're off working on several things that folks have been emailing us about, so we thought it'd be good to provide some detail:
* The next class pack will be the Scout. One of the main goals we're focusing on for him has been to provide tools that make him useful in maps like Dustbowl & Goldrush. If you have any ideas for what you think would work well, post them over on the Team Fortress 2 Forum and we'll take a look.
* We are actively working on a massive XBox 360 update, which will include pretty much everything we've shipped on the PC in the last year. We'll provide you with a rough date when we have one.
* We're also working on bringing over a variety of engine improvements from Left 4 Dead into the TF2 engine, but it won't be a wholesale replacement of the engine. This means we'll get some of L4D's performance improvements, like the better multicore support, but not all of them. For example, we can't bring over some improvements without dropping support for DX8, which we're not prepared to do.